Shockproof electromagnetic contactor



May 28, 1963 T. F. ROSING SHOCKPROOF ELECTROMAGNETIC CONTACTOR 3Sheets-Sheet 2 Filed Oct. 5, 1960 IIIIII'! NAAANNNNNI May 28, 1963 T. F.ROSING SHOCKPROOF ELECTROMAGNETIC CONTACTOR 3 Sheets-Sheet 3 Filed 000.5, 1960 3,091,677 Patented May 28, 1963 SHOCKPROOF ELECTROMAGNETICCGNTACTQR Theodore F. .Rosing, Whitefish Bay, Wis, assignor toCutler-Hammer, Inc, Milwaukee, Wis, a corporation of Delaware Filed Oct.5, 1960, Ser- No. 60,659 Claims. 31. 200-103) This invention relates toa shockproof electromagnetic switch designed for alternating currentoperation.

A primary object of the invention is to provide a highly compact switchfor use at relatively high voltages in the range of 2,000 to 5,000volts.

Another object is to provide such a switch in which the contacts may bequickly inspected and replaced if necessary.

The first object is accomplished by providing (1) va compact rollerguide shockproof linkage construction and (2) encapsulated blow-outcoils having physically smaller laminated wound cores producing therequired blow-out field. The roller guide assembly requires less spacethan common shockproof linkages because of the rectilinear motion of thecontact carrying carriages and the fact that the roller support willcarry larger loads with smaller area as well as having low frictionoperation. The cylindrically wound cores are easier to manufacture thanconventional cores. Their use also reduces the size of the coilconstruction and facilitates in manufacture.

Other objects and advantages will be pointed out in, or be apparent fromthe specification and claims, as will obvious modifications of thesingle embodiment shown in the drawings in which:

FIGURE 1 is a side view of a shockproof contactor embodying theinvention with a portion broken away to show contact structure;

FIG. 2 is a top view of only the contact carrying portion of thecontactor;

FIG. 3 is a sectional view taken along the line 33 of FIG. 2;

FIG. 4 is a front elevational view of only the contact carrying portionof the contactor;

FIG. 5 is a view in side elevation of only the blowout coil and arechute portion of the contactor;

FIG. 6 is a side view of a compact blow-out coil;

FIG. 7 is an end view of such blow-out coil; and

FIG. 8 is a perspective view of a cylindrical laminated wound core for ablow-out coil.

Referringto the drawings, the invention is shown embodied in ashockproof electromagnetic switch which has a contact carrying portion16 and a blow-out coil and are chute portion both mounted on a verticalframe 14; the contact carrying portion being mounted so that it may beswung downward to expose the contacts for inspection and replacement.

The blow-out coil and are chute portion has an upper insulator arcattenuating section 10 of usual design including arc runners 1'1.Closely below the arc runners there is positioned a pair of blow-outcoils 13 wound on laminated cores or pole pieces 12 that are secured bybolts 19 passing through an insulator panel 17. The panels 17 haveopenings 17a through which the cores project to make good magneticconnection with the pieces 12. The blow-out coil has been improved intoa more compact structure. This has been accomplished by encapsulatingthe coil winding with epoxy resin 27 or the like, and then coring acircular bore 29 in the insulative resin through the inside of the coilwinding 25. A laminated cylindrical Wound core 31 (see FIG. 8), formedby rolling a strip of suitable magnetic material, is inserted in thecylindrical bore. This core construction is much more compact than thoseof conventional design which employ stackedplates to form the coil core.The present coil, because of its reduced size made possible by thisnew-type core, can be nested closely below the arc runners withouthaving to unduly spacethe contact carrying assembly below the bottom ofthe arc chutes 10, or Without having the coil projecting outwardly tothe front or rear of the arc chutes. Compactness is essential in manyuses of this type of shockproof switch,

and the improved blow-out coil design contributes to the overall sizereduction of the present switch. Flux from a front blow-out coil entersthe pole piece and then passes into the contact gap where it interactswith the flux pro .duced by the arc to exert an upward force on the arcin the gap. The back blow-out coil creates a similar fieldand thesefields force the are created upon contact separation from the contactsto the arc runners 11 along the arc runners and up into the arc chutes10 so that the arc is attenuated and thereby extinguished.

The contact carrying portion 16 has pairs of opposed contacts 18, 20mounted on a shockproof linkage (described below) which is carried byspaced channel shaped horizontal frame members 32. The horizontal framemembers 32 are pivotally secured to the vertical frame 14 in a mannerdescribed in detail below. The contacts project upward into operativerelation with the blowout coil and arc chute portion of the contactor.

The shock proof linkage consists of identical and oppositelyactingcarriageassemblies. One carriage assembly includes an E-shapedarmature 21 and one or more fixed contacts 18 fixed to a support plate26 which in turn is fixed to the upper flanges of channels 26, 26. Eachof the channe1s26 ride on pairs of spaced rollers 28, 28

which rotate on bolts 30 secured to the Web of each of the horizontalframe members 32. The other carriage assembly includes a like butoppositely displaced E- shaped armature 22 and one or more contacts 20mounted on a supportplate 24 which in turn is fixed to the lower flangesof spaced apart channels 29, .29. Each of the channels 29' ride onspaced rollers 31, 31 which rotate on bolts 30 secured to the webs ofthe horizontal framemembers 32. An encapsulated energizing coil 35 issecured to a mounting bracket 33 which is secured to the horizontalframe member 32, and each armature is positioned on its respectivesupport plate so that its cent-er leg 34- is attracted to the coilinterior when the coil is energized.

This arrangement results in a compact structure inasmuch as it permitsthe channels of each pair to overlap the carriage member to which theyare not attached thereby permitting the support rollers to be spacedapart the entire depth of the assembly thereby maximizing the supportspan without increasing the depth of the contactor. A link 40 is pivotedto each of the horizontal frame members 32 at the n1id-portion 42 of thelink and has slotted ends 4-4 into which pins 46, which are fixed toadjacent channels 26 and 29 extend. The slotted ends of the linkaccommodate the lateral motion inherent in this linkage when theadjacent channels 26 and 29 move with respect to one another andmaintain an operative connection between the channels throughout suchmovement.

Thus, when a shock is exerted along the line of movement of thecarriages, one carriage produces a clockwise force moment about thepivot point of the link, and the other carriage produces an equalcounterclockwise force moment with a resultant cancellation of theeffect of the shock force so that the carriages, and hence the contacts,remain in whatever position they occupied at the moment of the shock.Springs 48 normally bias the carriages apart, but when the coil isenergized the armatures are attracted and the springs are overcome.

Each contact is connected through a lead 50 to one end of a coil winding25 forming part of a blow-out coil 13. These leads are slack when thecoil is deenergized so that when the coil is energized the leads do notinhibit carriage travel. The leads connecting the front contacts 20 totheir blow-out coils are detachable for reasons next described. It isoften desirable to inspect the main contacts 18, 20 and to this end, thehorizontal frame member 32 is pivoted to the vertical frame member 14 sothat the contact carrying portion of the contactor may be swung down toexpose the contacts. The horizontal frame member is normally supportedby two spaced bolts 72, 74 at the top and one bolt 75 at the bottom. Onetop bolt hole 76 communicates with an inclined slot '78 so that theentire contact carrying portion may be swung down by removing bottombolt 75 and loosening bolts 72 and 74. This is done :on both sides ofthe symmetrical frame and detachable leads 50 are detached from thefront blow-out coil winding. The contact carrying portion is then freeto pivot on bolt 74, and bolt 72 slides to the end of slot 78 whichlimits the downswing of the contact carrying portion of the contactor.The horizontal frame is tapered adjacent to the vertical frame so thatit does not interfere with the downswing. This tapered portion may buttagainst the vertical frame and stop the downswing under certaintolerance conditions but, in any event, a stop on the downswing isprovided by either the bolt reaching the end of the slot or by thehorizontal frame butting against the vertical frame. Of course, the sameswingdown action is secured if the slot is placed adjacent a bolt holein the horizontal frame member.

Interlock switch mechanism 65, which forms no part of this invention, ofthe sliding engagement type for controlling auxiliary circuits isprovided with one movable actuator bar fixed to one carriage through arm66 and another movable actuator similarly fixed to the other carriagethrough arm 70.

Although but one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. In a shockproof electric switch, a frame, rollers rotatably mountedon said frame, a pair of contact carrying carriages which are eachsupported and movable on said rollers with respect to said frame, anelectromagnetic coil carried by said frame, a pair of armaturesrespectively mounted on said carriages in line with said coil, andlinkage means interconnecting said carriages so that the masses of saidcarriages and their armatures oppose 4 each other under shock so thattheir positions are unaffected.

2. The combination according to claim 1 in which the movement of saidcarriages includes a common plane, one carriage including a channellying above and closely adjacent said common plane, the other carriageincluding a channel lying below and closely adjacent said common planewhereby the height of the contactor is held to a minimum.

3. The combination according to claim 1 in which the supported portionof each carriage overlaps a portion of the other carriage whereby thedepth of the contactor is held to a minimum.

4. The combination according to claim 1 in which said linkage meanscomprises a member pivoted on said frame and having a longitudinal slotin each end, each carriage having a pin extending therefrom, the pin onone of said carriages extending into the slot in one end of said linkand the pin on the other of said carriages extending into the slot inthe other end of said link.

5. An electromagnetic shockproof switch for actuation by alternatingcurrent comprising, a frame, a coil carried by said frame, a first pairof rollers rotatably fixed to said frame, a first member guided by saidfirst pair of rollers, a first support plate fixed to the bottom of saidfirst member, a first armature carried by said first support plate formovement toward and away from said coil, a first contact also carried bysaid first support plate, a second pair of rollers rotatably fixed tosaid frame, each pair of rollers being mounted so that a line throughthe centers of one pair is parallel with a line through the centers ofthe 'other pair, a second member guided by said second pair of rollers,a second support plate fixed to the top of said second member, a secondarmature carried by said second support plate for movement toward andaway from said coil, a second contact also carried by said secondsupport plate, said contacts positioned to contact when said coil isenergized, and a link pivoted at its mid-point to said frame and havingone end connected to said first member and the other end connected tosaid second member, the total mass of said first support plate, firstmember, first contact and first armature being equal to the total massof said second support plate, second member, second contact and secondarmature whereby said first and second members act equally andoppositely under shock.

References Cited in the file of this patent UNITED STATES PATENTS2,223,105 Howe Nov. 26, 1940 2,474,742 Kuhn June 28, 1949 2,756,302Baltuch July 24, 1956 2,794,882 Russell June 4, 1957

1. IN A SHOCKPROOF ELECTRIC SWITCH, A FRAME, ROLLERS ROTATABLY MOUNTEDON SAID FRAME, A PAIR OF CONTACT CARRYING CARRIAGES WHICH ARE EACHSUPPORTED AND MOVABLE ON SAID ROLLERS WITH RESPECT TO SAID FRAME, ANELECTROMAGNETIC COIL CARRIED BY SAID FRAME, A PAIR OF ARMATURESRESPECTIVELY MOUNTED ON SAID CARRIAGE IN LINE WITH SAID COIL AND LINKAGEMEANS INTERCONNECTING SAID CARRIAGE SO THAT THE MASSES OF SAID CARRIAGEAND THEIR ARMATURES OPPOSE EACH OTHER UNDER SHOCK SO THAT THEIRPOSITIONS ARE UNAFFECTED.